SK10982002A3 - Pharmaceutical composition comprising pemetrexed together with monothioglycerol L-cystein or thioglycolic acid - Google Patents

Abstract

The present invention provides a pharmaceutical composition comprising pemetrexed; at least one antioxidant selected from the group consisting of monothioglycerol, L-cysteine, and thioglycolic acid; and apharmaceutically acceptable excipient. The pharmaceutical formulation is suitable for liquid parenteral administration.

Description

Technical field

The present invention relates to a liquid composition comprising the known pemetrexed compound, in particular. the present invention relates to a liquid composition comprising pemetrexed and an antioxidant; this liquid composition is stable and pharmaceutically elegant.

BACKGROUND OF THE INVENTION

Certain antimetabolites of folic acid are known to be antineoplastic agents. These compounds inhibit the enzymatic conversion of metabolic folic acid derivatives. One such compound, described in US Patent 5,344,932, is currently being developed for possible use as a pharmaceutical agent. This compound, known as "pemetrexed", is most preferably formulated as a concentrated liquid for administration as an infusion dose. The disodium salt of pemetrexed is an active ingredient of the anticancer ALIMTA, which is at the stage of clinical development of Eli Lilly and Company.

The conclusions set forth in US Patent 5,344,932 state that the claimed compounds can be administered parenterally.

A solution that is easy to use, stable, reconstitutable and storable at ambient temperature is particularly desirable for drugs such as pemetrexed, where such ready-to-use formulation provides easier and safer handling, storage and distribution.

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It is particularly desirable that a stable formulation can be prepared without the use of lyophilization. The desired liquid formulation can bring increased safety to the treating person working with cytotoxic materials. In addition, a stable and easy to use formulation is more acceptable to the customer.

It has been found that a simple isotonic saline solution of pemetrexed is not pharmaceutically acceptable for commercial purposes due to degradation of the solution which generates unacceptable related substances. It has now been found that pharmaceutically acceptable, concentrated, easy to use liquid solutions of pemetrexed can be prepared as long as the formulation includes certain antioxidants, including monothioglycerol, L-cysteine and thioglycolic acid. Other antioxidants have been studied, but it has surprisingly been found that only the antioxidants mentioned above provide the desired properties of the formulation described below.

The formulation of the present invention exhibits acceptable stability, retains a pharmaceutically acceptable appearance, retains the desired enantiomeric stability, and meets the physician's desire for a stable and easy to use liquid formulation. In addition, the composition described herein is suitable for parenteral dosing, can be administered to the attending physician in a transparent vial, and can be stored at temperatures above 4 (four) degrees Celsius in a highly concentrated state.

The present invention is directed to a need for a pharmaceutically stable liquid pemetrexed formulation that has both color stability and acceptable storage stability in terms of preserving a solution form and avoiding unacceptable degradation to unacceptable related substances. In addition, the formulations of the present invention may be diluted to the desired concentration for administration by the attending person. Finally, the compositions described herein do not require the addition of any preservative other than an antioxidant in order to maintain the desired concentration and stability.

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SUMMARY OF THE INVENTION

The present invention relates to a pharmaceutical composition comprising:

(a) pemetrexed;

(b) at least one antioxidant selected from the group consisting of:

i) monothioglycerol, ii) L-cysteine, iii) thioglycolic acid, and

c) a pharmaceutically acceptable excipient.

The three antioxidants are the only ones that are effective in the composition of the present invention. It has surprisingly been found that conventional antioxidants such as sodium metabisulfite, ascorbic acid, sodium EDTA, monoethanolamine gentisate, sodium formaldehyde sulfoxylate and sodium bisulfite do not provide the desired properties of the formulation.

A particularly preferred antioxidant is monothioglycerol.

The concentration of monothioglycerol is most preferably from about 1 part per million to 8.0 mg / ml and the concentration can be optimized for a given formulation based on the concentration of oxygen coming into contact with the formulation. The concentration of monothioglycerol may preferably be at least 0.6 mg / ml, more preferably at least 0.8 mg / ml, particularly preferably at least 1.0 mg / ml. The concentration of monothioglycerol is preferably up to 6 mg / ml, more preferably up to 5 mg / ml

And is most preferably up to 5 mg / ml.

It may be preferred that the concentration of monothioglycerol be from about 0.6 mg / ml to about 6 mg / ml. More preferably, the concentration of monothioglycerol is from about 0.8 mg / ml to about 5.0 mg / ml. A monothioglycerol concentration of at least 1.0 mg / ml is particularly preferred. A particularly suitable concentration is from 1.40 mg / ml to about 3.0 mg / ml. Another desired concentration is from about 2 mg / ml to about 3 mg / ml.

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Another preferred concentration of monothioglycerol is from about 1.2 mg / ml to about 2.4 mg / ml.

Generally, the concentration of monothioglycerol, L-cysteine or thioglycolic acid is most preferably from about 1 part per million to 8.0 mg / ml and the concentration can be optimized for a given formulation based on the oxygen concentration coming into contact with the formulation. L-cysteine or thioglycolic acid is often most effective at higher pH. It may be preferred that the concentration of monothioglycerol, L-cysteine or thioglycolic acid is from about 1.0 mg / ml to about 6 mg / ml. More preferably, the concentration of monothioglycerol, L-cysteine or thioglycolic acid is from about 0.8 mg / ml to about 5.0 mg / ml. It is particularly preferred that the concentration of monothioglycerol, L-cysteine or thioglycolic acid is at least 1.0 mg / ml. A particularly desirable concentration of monothioglycerol, Lcysteine or thioglycolic acid is from 1.40 mg / ml to about 3.0 mg / ml. Another desired concentration is from about 2 mg / ml to about 3 mg / ml. Another preferred concentration of monothioglycerol, L-cysteine or thioglycolic acid is from about 1.2 mg / ml to about 2.4 mg / ml. A concentration of about 0.1 (one-tenth) mg / ml to 7 mg / ml is preferred. When the antioxidant is monothioglycerol or L-cysteine, a preferred concentration range is from about 0.1 (one-tenth) mg / ml to about 10.0 mg / ml.

The concentration of L-cysteine is preferably greater than 0.1 (one-tenth) mg / ml, more preferably greater than 0.5 (one-half) mg / ml and most preferably greater than 1 (one) mg / ml.

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The concentration of L-cysteine is preferably less than 10 (ten) mg / ml, more preferably less than 8 (eight) mg / ml, and most preferably less than 6 (six) mg / ml. The thioglycolic acid concentration is preferably greater than 0.1 (one-tenth) mg / ml, more preferably greater than 0.5 (one-half) mg / ml, and most preferably greater than 1 (one) mg / ml.

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The concentration of thioglycolic acid is preferably less than 10 (ten) mg / ml, more preferably less than 8 (eight) mg / ml and most preferably less than 6 (six) mg / ml.

In addition, combinations of three antioxidants selected from monothioglycerol, L-cysteine and thioglycerol may also be used according to the present invention.

The concentration of pemetrexed is preferably from about 20 to about 100 mg / ml. A particularly preferred concentration of pemetrexed is from about 30 mg / ml to about 70 mg / ml. Another preferred embodiment is when the concentration of pemetrexed is from about 35 mg / ml to about 50 mg / ml. Another preferred embodiment is a pemetrexed concentration of from 38 mg / ml to about 44 mg / ml. A particularly preferred concentration of pemetrexed is about 40 mg / ml.

As used herein, the term "pemetrexed" refers to its stable forms of salts, acids and free base. The term includes, for example, free acid, pharmaceutically acceptable salts of alkali metals, alkaline earth metals, non-toxic metals, ammonium and substituted ammonium salts such as sodium, potassium, lithium, calcium, magnesium, aluminum, zinc, ammonium, trimethylammonium, triethylammonium, monoethanolammonium. , triethanolammonium, pyridinium salt, substituted pyridinium and the like. Substituted ammonium salts are a particularly preferred group of salts.

As used herein, the term "pharmaceutically acceptable excipient" means a pharmaceutically acceptable carrier, solution, or additive

The properties of the formulation. Such additives are well known to those skilled in the art. While any pharmaceutically acceptable diluent is suitable, a particularly preferred excipient for parenteral administration is a saline solution, such as sodium chloride, mannitol, and the like.

Pemetrexed disodium salt is particularly preferred for use in the formulation of the present invention.

The pH of the formulation is most preferably from about 5.5 to about 12. The formulation more preferably has a pH of from about 7 to about 11. A pH of from 8.0 to 9.0 is particularly desirable. It is further preferred that the pH be from about 8 to about 9 when the antioxidant is monothioglycerol. If the antioxidant is L-cysteine or thioglycolic acid or any salt thereof, then the preferred pH is from about 8 to about 10. Those skilled in the art will appreciate that combinations of said antioxidants may indicate a new preferred pH range. Standard modifications of the compositions may provide compositions of varying pHs within the scope of the present invention.

A generally preferred method of preparing the formulation involves the use of an inert gas stream. Such inert gases are, for example, nitrogen, argon and the like. The use of an insulator to maintain a low oxygen state is desirable but not necessary for storing the composition of the present invention.

While any pharmaceutically acceptable closure can be used to close the container containing the formulation, it is preferred to close the container with a closure that is siliconized. A sterilized cap coated with Teflon is desirable to close the container.

Any pharmaceutically acceptable container or container may be used to store the composition of the present invention. Desirably, the container containing the formulation minimizes the concentration of oxygen that comes into contact with the formulation. Therefore, vials or ampoules are particularly desirable for storing the composition of the present invention. Closed bottles are especially required for commercial purposes in most countries. '.

The skilled artisan will appreciate that the use of depyrogenated prewashed vials is desirable for the storage of sterile liquid formulations intended for parenteral use. The vial may be colored; however, transparent vials are acceptable for storage of the formulation. Any pharmaceutically acceptable material can be used to make the packaging for the formulation, but glass is a particularly preferred packaging material for the formulation.

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A glass bottle is a preferred container. Other packaging materials for parenteral formulations, such as plastic bottles, are also a preferred option. For example, plastic vials may be used.

It may be desirable to protect the solution from light during preparation of the formulation; however, such protection is not necessary for the composition of the present invention.

The resulting formulation can be sterilized using methods known to those skilled in the art. Such sterilization methods may include, for example, sterile filtration or heating. It is particularly favorable that the claimed composition is stable during heat sterilization.

Preferably, the top of the vial contains less than about 8% (eight percent) by volume. O; however, the top of the vial may contain more than 8% oxygen as long as the other properties of the formulation are suitably modified. More preferably, the top of the vial contains from about 2% to about 5% oxygen. It is particularly preferred that the top of the vial contains from about 3% to about 5% oxygen. It is further preferred that the top of the vial contains less than about one (1) ppm oxygen. It is also preferred that the oxygen content of the top of the vial be less than about 0.1% (one-tenth percent) by volume. oxygen. It is also preferred that the top of the vial contains less than about 1% (one percent) oxygen.

The top of the vial can be adjusted to minimize contact of the formulation with oxygen. Generally, it is desirable that the top of the vial t1 does not represent more than about 1/3 (one-third) of the total volume of the container, with the filling occupying at least about 2/3 (two-thirds) of the total volume of the container. For example, it may be preferred that a 5 ml cartridge be used in the case of a 7.5 ml bottle. If a larger volume of the top of the vial is desired, then the concentration of antioxidant may be adjusted as necessary.

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The pharmaceutical composition of the present invention is suitable for both clinical use in human medicine and veterinary use in animals.

Pemetrexed may be prepared as described in U.S. Patent 5,473,071, which is incorporated herein by reference in its entirety. Pemetrexed compositions are useful for the treatment of cancer as described in Patent 5,344,932, as well as in Seminars in Oncology, Vol. 26, no. 2, Appendix 6 (April 1999).

Monothioglycerol is commercially available from noble chemical supply companies well known to those skilled in the art. For further clarification, monothioglycerol has a Chemical Abstracts number of 96-27-5.

Similarly, L-cysteine (CAS: 52-90-4), Lcysteine monohydrate hydrochloride (CAS: 7048-04-6), L-cysteine anhydrous monohydrate (CAS: 52-89-1) and thioglycolic acid (CAS: 68- 11-1) are readily available from a company supplying noble chemicals.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is illustrated in more detail by the following examples.

Example 1

Pemetrexed was prepared as a 40 mg / ml solution in water. Monothioglycerol was prepared as a 2.4 mg / ml aqueous solution for injection. The pH of the monothioglycerol solution was adjusted to 8.5 using sodium hydroxide.

The solution was protected from light. The solution was under nitrogen for twenty minutes and then sterile filtered. The formulation was placed in prewashed, depyrogenated vials and then sealed with a prewashed and pre-sterilized cap coated with Teflon. The cap

The 972 / B closure was attached using a closure device. Sterile filtration and loading steps were performed using a nitrogen isolator (5% v / v).

O).

Solution-filled vials were heat-sterilized.

Example 2

The pharmaceutical composition was prepared essentially as described in Example 1, but 0.03% L-cysteine was used as an antioxidant and the concentration of pemetrexed was 4%.

Example 3

The pharmaceutical composition was prepared essentially as described in Example 1, but 0.03% thioglycolate was used as an antioxidant and the concentration of pemetrexed was 4%.

Claims (20)

PATENT CLAIMS A pharmaceutical composition comprising: (a) pemetrexed; (b) at least one antioxidant selected from the group consisting of: i) monothioglycerol, ii) L-cysteine, and iii) thioglycolic acid, and c) a pharmaceutically acceptable excipient. Pharmaceutical composition according to claim 1, characterized in that the composition is a liquid preparation suitable for parenteral administration. Pharmaceutical composition according to either of Claims 1 and 2, characterized in that the pemetrexed is in the form of its disodium salt. A pharmaceutical composition according to any one of claims 1 to 4. 3, characterized in that the antioxidant is monothioglycerol. The pharmaceutical composition of any one of claims 1 to 4, wherein the concentration of monothioglycerol is from about 1 to about 1 to about 8 (eight) milligrams per milliliter. 31,972 / B The pharmaceutical composition of claim 5, wherein the concentration of monothioglycerol is from about 1 (one) mg / ml to about 6 (six) mg / ml. The pharmaceutical composition of claim 6, wherein the concentration of monothioglycerol is from about 1 (one) mg / ml to about 2.5 (two and one half) mg / ml. The pharmaceutical composition of claim 4, wherein the concentration of monothioglycerol is from about 0.5 (one half) mg / ml to about 3 (three) mg / ml. Pharmaceutical composition according to any one of claims 1 to 3, characterized in that the antioxidant is L-cysteine. The pharmaceutical composition of claim 9, wherein the concentration of L-cysteine is from about 10 parts per million to about 8 (eight) mg / ml. The pharmaceutical composition of claim 10, wherein the concentration of L-cysteine is from about 1 (one) mg / ml to about 6 (six) mg / ml. ''; Pharmaceutical composition according to claims 1 to 3, characterized in that the antioxidant is thioglycolic acid. 31,972 / B The pharmaceutical composition of claim 12, wherein the concentration of thioglycolic acid is from about 1 (one) part per million to about 8 (eight) mg / ml. The pharmaceutical composition of claim 13, wherein the concentration of thioglycolic acid is from about 0.1 (one-tenth) mg / ml to about 6 (six) mg / ml. The pharmaceutical composition of claim 4, wherein the concentration of monothioglycerol is from about 0.1 (one tenth) mg / ml to about 10 (ten) mg / ml. The pharmaceutical composition of claim 15, wherein the concentration of monothioglycerol is from about 0.1 (one tenth) mg / ml to about 6 (six) mg / ml. The pharmaceutical composition of claim 9, wherein the L-cysteine is from about 0.1 (one tenth) mg / ml to about 10 (ten) mg / ml. The pharmaceutical composition of claim 17, wherein the L-cysteine is from about 0.1 (one-tenth) mg / ml to about 6 (six) mg / ml. The pharmaceutical composition of claim 12, wherein the thioglycolic acid is from about 0.1 (one tenth) mg / ml to about 10 (ten) mg / ml. 31,972 / B The pharmaceutical composition of claim 19, wherein the thioglycolic acid is from about 0.1 (one-tenth) mg / ml to about 6 (six) mg / ml.